Technical Field
The present invention relates to additive manufacturing powder and a method of manufacturing the additive manufacturing powder.
Background Art
A group of technologies to manufacture three-dimensional objects using solid form data created by three dimensional computer aided design system (3D CAD), etc. is referred to as rapid prototyping technologies. By using molding technique for heat-resisting powder of these technologies, molds or cores can be manufactured without using a model or pattern so that casting production processes becomes extremely short. The rapid prototyping technologies are also referred to as additive manufacturing methods, by which a 3D object is produced by laminating cross sections thereof. In addition, the rapid prototyping technologies includes various layer manufacturing methods (powder fixing methods) using powder as a material.
Conventionally, artificial bones are made of metal materials such as stainless and titanium alloy and abrasion resisting plastic and used for bone replacement operation. These artificial bones substitute malfunctioning joints to fulfill joint function. However, metal materials and wear resistant plastic deteriorate with age due to abrasion, corrosion, swelling, etc. so that they are not suitable for use for a long period of time. Ceramics based on calcium phosphate are now used instead of these materials. Currently, such ceramics are used to provide a scaffold to form bones or promote formation of new bones while being absorbed in bones with time to be substituted with the bones in the future.
As bone prosthetic materials to provide a scaffold for bone formation, for example, materials such as hydroxyapatite having excellent affinity with bone tissue and directly bondable with bone tissue without inclusion are used in many cases. By embedding the bone prosthetic material into the bone defect portion, bone repair is conducted quickly using the bone prosthetic material as a scaffold.
However, bone replacement does not occur by simple hydroxyapatite, hyroxyapatite remaining in a biological body may cause a problem. On the other hand, when the bone prosthetic material with which substitutes bones is embedded into bone tissue, osteogenetic function of the bone tissue is promoted, so that the bone is repaired more easily and more quickly.
As the bone prosthetic material with which bones are substituted, a specific example thereof is tricalcium phosphate (TCP). The degree of tricalcium phosphate absorbed in bones depends on the form of tricalcium phosphate compact. That is, porous tricalcium phosphate has large specific surface area in terms of form and are easily absorbed in bone tissue and are vulnerable to attack of phagocytic cells. To the contrary, dense tricalcium phosphate is extremely slowly absorbed and not easily attacked by phagocytic cells. By combining porous portions and dense portions utilizing such form differences, expression of desired biological compatibility is expected. However, such a combined material is not strong enough to be applied to bones such as thighbone receiving heavy burden. Moreover, it takes longer hours to mold and process the material into a desired form and in particular in the case of a structure having an inside structure, fine processing is impossible by cutting (slicing).
These powder additive manufacturing methods are advantageous in terms of fine processing but requires some devisal to shape a material such as ceramics or carbon fiber which has an extremely high melting point and is not melted by typical laser beams